This invention relates generally to article handling apparatus and more specifically to an apparatus for rapidly removing molded articles from plastic molding machines, as well as articles formed by various other manufacturing processes. A number of systems are known in the prior art for removing molded articles following ejection of those parts from a conventional injection molding machine, for example. Included are simple systems in which molded articles are permitted to drop from the mold after ejection, labor intensive manual systems, conveyor systems that transport the articles after they have been ejected, and more complex mechanical grasping and suction systems that serve to remove the ejected articles. The prior art manual systems result in contamination of dropped articles and the need for additional subsequent handling. The prior art mechanical grasping and suction systems are disadvantageous in that they suffer from slow operating speeds. In today's manufacturing processes, it is important to increase the output of manufactured articles to control the cost of production and thereby maintain a competitive position in the marketplace. This need for high output is particularly important in the plastic molding industry, for example, where molding cycles may be no more than a few seconds. The production rate in this industry has been limited by the inability of prior art article handling devices to rapidly retrieve molded parts from a mold so that a new molding cycle may begin.
It is therefore a principal object of the present invention to provide a retrieval system for rapidly removing articles from a plastic molding machine or other manufacturing process to significantly shorten the manufacturing cycle time over prior art manufacturing processes that employ automated article retrieval systems. The speed advantage afforded by the present invention is achieved by realizing acceleration rates on the order of 22 G's as compared to acceleration rates in prior art direct drive robot systems of typically 5.7 G's. This and other objects are accomplished in accordance with the illustrated preferred embodiment of the present invention by providing a pair of lightweight non-metallic telescoping tubes arranged for telescoping motion into and out of an open mold. The telescoping tubes are driven by a low inertia cable drive system. A high volume vacuum is supplied to the telescoping tubes and, in turn, to a set of receivers mounted on the telescoping tubes to rapidly draw molded articles from the mold as they are conventionally ejected therefrom. A differential vacuum sensing system provides confirmation that all of the molded articles have been drawn from the mold by the receivers. The telescoping non-metallic tubes, with the molded articles just retrieved, may then be instantaneously withdrawn from the open mold to permit early closing of the mold so that a new molding cycle may be initiated.